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  <title>Document</title>
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  <script>
    function test(bool) {
      return new Promise((resolve, reject) => {
        if (bool) {
          resolve("成功")
        } else {
          reject("失败")
        }
      })
    }
    // finally promise的兜底操作
    test(true).then(res => {
      console.log(res)
    }).catch(err => {
      console.log(err)
    }).finally(res => {
      console.log("总是执行的函数")
    })




  </script>
</body>

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